Thomas a



(No Model.)

T A. EDISON.

ORE SCREENING APPARATUS. A No. 476,532. Patented June 7, 1892.

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JY M W 1 I a 1 Hoa /@131 M. WA w W UNITED STATES PATENT Orrrcn.

THOMAS A. EDISON, OF'LLEWELLYN PARK, NEW JERSEY.

ORE-SCREENlNG APPARATUS.

SPECIFICATION forming part of Letters Patent No. 476,532, dated June 7,1892.

Application filed October 15, 1891- Serlal No. 408,756. (No model.)

To aZZ- whom, it may concern;

Be it known that I, THOMAS A. EDISON, a citizen of the United States,residing at Llewellyn Park, in the county of Essex and State of NewJersey, have invented a certain new and useful Improvement inOre-ScreeniugApparatus, (Case No. 9H,) of which the following is aspecification.

The object of the present invention is to provide an apparatusforkeeping the screenpe'rforations free from obstruction by lumps of oretoo large to readily pass through them; and the invention consists inthe combination, with a screening apparatus, of wire pad or cardcleaners, as hereinafter set forth and claimed.

In the accompanying drawings, Figure 1 is an end view, partly insection, of ascreeningcylinder and myimproved cleaning device inposition to operate therein. Fig. 2 is a plan view of a short section ofthe cylinder.

The present invention constitutes an improvement on the circular wirecleaning-brush described in my application, Serial No. 407,459.

In the drawings, 1 is the screening-cylinder, which may be mounted androtated in any suitable manner. In the cylinder are numerousperforations 2, which are preferably in the form of narrow slits cfconsiderablelength. The cylinder may be perforated directly, as shown inFig. 1,with these small perforations, or the small perforations may bein covers, which are placed over large openings in the cylinder, as setforth in my application above referred to.

3 are circumferential ribs for strengthening the cylinder and betweenwhich the brushes rest.

at is a wire-card brush having a back of canvas, belting, or othersuitable material and having wire teeth 5. These teeth are prefer ablytwo or two and a half inches long and bent as indicated. Several ofthese brushes are mounted side by side on a supporting-bar 7, asindicated in Fig. 2, in which figure they are shown rubbing on thecylinder between the ribs. The brushes used are preferably two feet ormore long and are allowed to rest by their own weight simply on thesurface of the cylinder, although in some cases additional weight may beadded to press themforward with greater force. It will be seen that thebrushes are of such length that they will be flexible and will bend tofollow the contour of the cylinder-surface. As the cylinder rotates, thewires of the brush are bent forward by the solid portions 6 of thecylinder and are then allowed to snap down into the slits orperforations. In this way any particles which have become wedged in theperforations from the inside are forced back into the cylinder. Thesebrushes are much simpler and cheaper than the circular brushes beforeused, and they are easier to mount; but I find that in practice they aremuch more efficient.

What I claim is- 1. The combination, with a rotary screen, of a card-wire-brush cleaner resting freely on the surface thereof, substantially asdescribed.

2. The combinatiomwith an ore-screen having elongated perforations, of acard-wirebrush cleaner resting freely on the surface thereof,substantially as described- 3. The combination, with an ore-screeningcylinder, of a long flexible card-wire-brush cleaner resting freely onthe surface thereof, whereby it will follow the contour of the cylinderand whereby the wire teeth will snap into the perforations to removeobstructions, substantially as described.

4. The combination, with an ore-screening ribbed cylinder, of flexiblecard-wire-brush cleaners resting freely on the surface thereof betweenthe ribs, whereby they will follow the contour of the cylinder,substantially as;

described.

5. The combination, with a rotary orescreening cylinder, of-a longflexible card-wirebrush cleaner fixed at its upper end toa suitablesupport and having its lower end free and resting against the cylinder,substantially as described.

This specification signed and witnessed this 8th day of October, 1891.

THOS. A. EDISON.

lVitnesses:

JOHN T. RANDOLPH, CHARLES M. CATLIN.

